1. Field of the Invention
This invention relates to a dye-forming material and process for producing a dye image by means of a dye-forming coupler and a ureidoaniline developing agent that is capable in its oxidized form of reacting with the dye-forming coupler. It also relates to a photothermographic material and a thermographic material and process for producing a dye image by means of such a coupler and developing agent.
2. Description of the State of the Art
Dye-forming imaging materials and processes are known for producing dye images by means of a dye-forming coupler and a reducing agent that is capable in its oxidized form of reacting with the dye-forming coupler. Such materials and processes are described in, for example, Research Disclosure, December 1978, Item No. 17643.
Silver halide photothermographic materials and processes for producing silver images and dye images are also known. Examples of such materials and processes are described in, for instance, U.S. Pat. Nos. 3,531,286 and 3,761,270. Such photothermographic materials comprise, in reactive association, (a) photographic silver halide, (b) a dye-forming coupler and (c) an oxidation-reduction image forming combination comprising (1) an organic silver salt oxidizing agent and (2) an organic reducing agent for the organic silver salt oxidizing agent wherein the organic reducing agent in its oxidized form reacts with the dye-forming coupler.
Phenylenediamine silver halide developing agents have been included in such imaging materials as the organic reducing agent. One problem encountered with these developing agents is that they do not enable a sufficiently wide optimum pH latitude for coating such imaging materials, especially such photothermographic materials and for dye formation. Another problem centers on the desire to replace the phenylenediamine developing agents with milder reducing agents in such photothermographic materials. No answer to these problems is found in the photographic art.
It has been desirable to replace the p-phenylenediamine silver halide developing agents in such imaging materials and processes with a milder developing agent that enables efficient, dye formation without such disadvantages and tendency to produce higher minimum density values than desired and that enables a water optimum pH range for coating and for dye formation.